trigonal (adjective)

1. In the fantasy novel, the mystical creatures inhabited a trigonal castle that represented the harmony of threefold symmetry.

2. The superhero's magical weapon had a trigonal shape that symbolized its threefold power.

3. The haunted mansion was adorned with eerie trigonal patterns that seemed to possess a sinister threefold symmetry.

4. In the futuristic spaceship, the control panel had buttons arranged in a trigonal formation, showcasing its advanced threefold design.